Not-so-smart quotes

I’d noticed that WP had been doing curly quotes wrong in a few of my posts and I’ve just put my finger on what it’s doing wrong. Basically if I put single quotes around a word beginning with lower-case s like, say, ‘salmon’, the opening quote mark is the wrong way round. Presumably it gets confused with s in particular because it thinks it’s in a possessive? Anyway, if anyone can suggest a fix, I’d be most grateful.

This happens irrespective of whether I use the visual editor, by the way. Oh, and this is WP2.1.2; I don’t remember it happening in 2.0.x, but I could be wrong.

Any ideas?